chapter 3 railway accident and serious incident investigations · chapter 3 railway accident and...

Chapter 3 Railway accident and serious incident investigations

Japan Transport Safety Board Annual Report 2014

41

1 Railway accidents and serious incidents to be investigated

<Railway accidents to be investigated>

◎ Paragraph 3, Article 2 of the Act for Establishment of the Japan Transport Safety Board

(Definition of railway accident)

The term "Railway Accident" as used in this Act shall mean a serious accident prescribed by

the Ordinance of Ministry of Land, Infrastructure, Transport and Tourism among those of the

following kinds of accidents; an accident that occurs during the operation of trains or vehicles as

provided in Article 19 of the Railway Business Act, collision or fire involving trains or any other

accidents that occur during the operation of trains or vehicles on a dedicated railway, collision or

fire involving vehicles or any other accidents that occur during the operation of vehicles on a

tramway.

◎ Article 1 of Ordinance for Enforcement of the Act for Establishment of the Japan

Transport Safety Board (Serious accidents prescribed by the Ordinance of Ministry of Land,

Infrastructure, Transport and Tourism, stipulated in paragraph 3, Article 2 of the Act for

Establishment of the Japan Transport Safety Board)

1 The accidents specified in items 1 to 3 inclusive of paragraph 1 of Article 3 of the

Ordinance on Report on Railway Accidents, etc. (the Ordinance);

2 From among the accidents specified in items 4 to 6 inclusive of paragraph 1 of Article 3 of

the Ordinance, that which falls under any of the following sub-items:

(a) an accident involving any passenger, crew, etc. killed;

(b) an accident involving five or more persons killed or injured;

(c) an accident found to be likely to have been caused owing to a railway officer's error in

handling or owing to malfunction, injury, destruction, etc. of the vehicles or railway

facilities, which resulted in the death of any person;

3 The accidents specified in items 4 to 7 inclusive of paragraph 1, Article 3 of the Ordinance

which are found to be particularly rare and exceptional;

4 The accidents equivalent to those specified in items 1 to 7 inclusive of paragraph 1, Article

3 of the Ordinance which have occurred relevant to dedicated railways and which are found

to be particularly rare and exceptional; and

5 The accidents equivalent to those specified in items 1 to 3 inclusive which have occurred

relevant to a tramway, as specified by a public notice issued by the Japan Transport Safety

Board.


50



42

[Reference] The accidents listed in each of the items of paragraph 1, Article 3 of the Ordinance

on Reporting on Railway Accidents, etc.

Item 1: Train collision

Item 2: Train derailment

Item 3: Train fire

Item 4: Level crossing accident

Item 5: Accident against road traffic

Item 6: Other accidents with casualties

Item 7: Heavy property loss without casualties

◎ Article 1 of the Public Notice of the Japan Transport Safety Board (Accidents specified by

the public notice stipulated in item 5, Article 1 of the Ordinance for Enforcement of the Act for


1 From among the accidents specified in items 1 to 6 inclusive of paragraph 1 of Article 1 of

the Ordinance on Reporting on Tramway Accidents, etc. (the Ordinance), that which falls

under any of the following sub-items:

(a) an accident that causes the death of a passenger, crewmember, etc.;

(b) an accident that causes five or more casualties;

2 The accidents specified in items 1 to 7 inclusive of paragraph 1 Article 1 of the Ordinance

which are found to be particularly rare and exceptional; and

3 From among the accidents occurring on a tramway operated under the application of the

Ministerial Ordinances to Provide Technical Regulatory Standards Railways mutatis

mutandis as specified in paragraph 1 of Article 3 of the Ordinance on Tramway Operations,

the accidents equivalent to those specified in items 1 to 3 of Article 1 of the Ordinance for

Enforcement of the Act for Establishment of the Japan Transport Safety Board.

[Reference] The accidents specified in the items of paragraph 1, Article 1 of the Ordinance on

Reporting on Tramway Accidents, etc.

Item 1: Vehicle collision

Item 2: Vehicle derailment

Item 3: Vehicle fire

Item 4: Level crossing accident

Item 5: Accidents against road traffic

51



43

Item 6: Other accidents with casualties

Item 7: Heavy property loss without casualties

Railway accidents to be investigated

*1: Among vehicle collisions, derailments, and fires on railways, accidents that fall under the category of level crossing accident,

accidents against road traffics , or other accidents with casualties and which involve the death of a passenger, crewmember, etc.

[Ordinance 1-2] or which are particularly rare and exceptional [Ordinance 1-3] are to be investigated.

(Note) “Ordinance” refers to the Ordinance for Enforcement of the Act for Establishment of the Japan Transport Safety Board;

“Notice” refers to the Public Notice by the Japan Transport Safety Board; and the numbers refer to the Article and

paragraph numbers.

Category

Tra

inco

llis

ion

Tra

ind

erai

lmen

t

Tra

infi

re

Lev

elcr

oss

ing

acci

den

t

Acc

iden

tag

ain

stro

adtr

affi

c

Oth

erac

cid

ents

wit

hca

sual

ties

Hea

vy

pro

per

tylo

ssw

ith

ou

tca

sual

ties

Railway(including tramway

operated as equivalentto railway)

[Notice 1-3]

All accidents(These refer to train accidentsand do not include vehicleaccidents on railways.*1)

[Ordinance 1-1]

・Accidents involving the death of a passenger,crew member, etc.

・Accidents involving five or more casualties・Accidents found to have likely been caused

by a railway worker's error in procedure ordue to the malfunction, damage, destruction,etc., of vehicles or railway facilities, whichresulted in the death of a person

[Ordinance 1-2]

Accidents that are particularly rare and exceptional[Ordinance 1-3]

Dedicated railway Accidents that are particularly rare and exceptional [Ordinance 1-4]

Tramway[Ordinance 1-5]

Accidents involving the death of a passenger, crewmember, etc., and accidentsinvolving five or more casualties

[Notice 1-1]

Accidents that are particularly rare and exceptional [Notice 1-2]

52



44

< Railway serious incidents to be investigated>

◎ Item 2, paragraph 4, Article 2 of the Act for Establishment of the Japan Transport Safety

Board (Definition of railway serious incident)

A situation, prescribed by the Ordinance of the Ministry of Land, Infrastructure, Transport

and Tourism (Ordinance for Enforcement of the Act for Establishment of the Japan Transport

Safety Board), deemed to bear a risk of accident occurrence.

◎ Article 2 of the Ordinance for Enforcement of the Act for Establishment of the Japan

Transport Safety Board (A situation prescribed by the Ordinance of the Ministry of Land,

Infrastructure, Transport and Tourism, stipulated in item 2, paragraph 4, Article 2 of the Act for


1 The situation specified in item 1 of paragraph 1 of Article 4 of the Ordinance on Reporting

on Tramway Accidents, etc. (the Ordinance), wherein another train or vehicle had existed in

the zone specified in said item;

[A situation where a train starts moving for the purpose of operating in the relevant block

section before completion of the block procedure: Referred to as “Incorrect management of

safety block.”]

2 The situation specified in item 2 of paragraph 1 of Article 4 of the Ordinance, wherein a

train had entered into the route as specified in said item;

[A situation where a signal indicates that a train should proceed even though there is an

obstacle in the route of the train, or the route of the train is obstructed while the signal

indicates that the train should proceed: Referred to as “Incorrect indication of signal.”]

3 The situation specified in item 3 of paragraph 1 of Article 4 of the Ordinance, wherein

another train or vehicle had entered into the protected area of the signal which protects the

zone of the route as specified in said item;

The scope of railway accident investigations has been modified since April 1, 2014:

Railway Accidents

○Any fatal accident that occurs at a level crossing without an automatic barrier machine is to be investigated.

○The criteria has been modified for the subject of investigations regarding level crossing accidents, accidents

against road traffic, or other accidents with casualties. It is now “A casualty figure of five or more, with at

least one of the casualties dead.”

○Any derailment accident involving a snowplow vehicle in operation has been excluded from the subject of

investigations (except for especially extraordinary cases).

Tramway Accidents

○Any fatal accident that occurs at a level crossing without an automatic barrier machine is to be investigated.

○The criteria for the subject of investigations has been modified to “A casualty figure of five or more, with at

least one of the casualties dead.”

53



45

[A situation where a train proceeds regardless of a stop signal, thereby obstructing the route

of another train or vehicle: Referred to as “Violating red signal.”]

4 The situation specified in item 7 of paragraph 1 of Article 4 of the Ordinance, which caused

malfunction, injury, destruction, etc. bearing particularly serious risk of collision or

derailment of or fire in a train;

[A situation that causes a malfunction, etc., of facilities: Referred to as “Dangerous damage

in facilities.”]

5 The situation specified in item 8 of paragraph 1 of Article 4 the Ordinance, which caused

malfunction, injury, destruction, etc. bearing particularly serious risk of collision or

derailment of or fire in a train;

[A situation that causes a malfunction, etc., of a vehicle: Referred to as “Dangerous trouble

in vehicle.”]

6 The situation specified in items 1 to 10 inclusive of paragraph 1 of Article 4 of the

Ordinance which is found to be particularly rare and exceptional; and

[These are referred to as: item 4 “Main track overrun”; item 5 “Violating closure section for

construction”; item 6 “vehicle derailment”; item 9 “Heavy leakage of dangerous object”; and

item 10 “others,” respectively.]

7 The situations occurred relevant to the tramway as specified by a public notice of the Japan

Transport Safety Board as being equivalent to the situations specified in the in preceding

items.

◎ Article 2 of the Public Notice of the Japan Transport Safety Board (A situation prescribed by

the public notice stipulated in item 7, Article 2 of the Ordinance for Enforcement of the Act for

Establishment of the Japan Transport Safety Board (Serious incident on a tramway))

1 The situation specified in item 1 of Article 2 of the Ordinance on Reporting on Tramway

Accidents, etc. (the Ordinance), wherein another vehicle operating on the main track had

existed in the zone specified in said item;

[A situation where a vehicle is operating on the main track for the purpose of operating in the

relevant safety zone before the completion of safety system procedures: Referred to as

“Incorrect management of safety block.”]

2 The situation specified in item 4 of Article 2 of the Ordinance, which caused malfunction,

injury, destruction, etc., bearing a particularly serious risk of collision, derailment of or fire

in a vehicle operating on the main track;

[A situation that causes a malfunction, etc., of facilities: Referred to as “Dangerous damage

in facilities.”]

3 The situation specified in item 5 of Article 2 of the Ordinance, which caused malfunction,

injury, destruction, etc., bearing a particularly serious risk of collision, derailment of or fire

in a vehicle operating on the main track;

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46

[A situation that causes a malfunction, etc., of a vehicle: Referred to as “Dangerous trouble

in vehicle.”]

4 The situation specified in items 1 to 7 inclusive of Article 2 of the Ordinance which is found

to be particularly rare and exceptional; and

[These are referred to as: item 2 “Violating red signal;” item 3 “Main track overrun;” item 6

“Heavy leakage of dangerous object;” and item 7 “others,” respectively.]

5 From among the situations occurring on a tramway operated under the application of the

Ministerial Ordinances to Provide Technical Regulatory Standards Railways mutatis

mutandis as specified in paragraph 1 of Article 3 of the Ordinance on Tramway Operations,

the situations equivalent to those specified in items 1 to 6 of Article 2 of the Ordinance for

Enforcement of the Act for Establishment of the Japan Transport Safety Board.

Serious incidents to be investigated

Category

・In

corr

ect

man

agem

ent

of

safe

tyb

lock

(Rai

lway

)・

Inco

rrec

tm

anag

emen

to

fsa

fety

blo

ck(T

ram

way

)

・In

corr

ect

ind

icat

ion

of

sig

nal

(Rai

lway

)・

Vio

lati

ng

red

sig

nal

Dan

ger

ou

sd

amag

ein

faci

liti

es

Dan

ger

ou

str

ou

ble

inv

ehic

le

・M

ain

trac

ko

ver

run

・V

iola

tin

gcl

osu

rese

ctio

nfo

rco

nst

ruct

ion

(Rai

lway

)・

Veh

icle

der

ailm

ent

(Rai

lway

)・

Hea

vy

leak

age

of

dan

ger

ou

so

bje

ct・

Oth

ers

Railway(including tramway

operated as equivalent torailway)

[Notice 2-5]

Certain conditions such as thepresence of another train

[Ordinances 2-1, 2-2, and 2-3]

Risk of collision,derailment or fire

[Ordinances 2-4/ 2-5]

Incidents that are particularly rare and exceptional [Ordinance 2-6]

Tramway[Ordinance 2-7]

Certainconditions suchas the presenceof a vehicle

[Notice 2-1]

Risk of collision,derailment or fire

[Notices 2-2 and 2-3]

Incidents that are particularly rare and exceptional [Notice 2-4]

(Note) “Ordinance” refers to the Ordinance for Enforcement of the Act for Establishment of the Japan Transport Safety Board;

“Notice” refers to the Public Notice by the Japan Transport Safety Board, and the numbers refer to the Article and

paragraph numbers.

55



47

2 Procedure of railway accident/incident investigation

Railway operatorTramway operator

District TransportBureau(Railway Department,etc.)

Minister of Land,Infrastructure, Transportand Tourism(Safety Administrator,Railway Bureau)

Report

・Interview with crew members, passengers, witnesses, etc.

・Collection of relevant information such as weather condition

・ Collection of evidence relevant to the accident and

examinations of damage to railway facilities and vehicles

・Railway committee

・General Committee or the Board for very serious cases in

terms of damage or social impact

Initial report to the Board

Comments from parties

concerned

Notification of railway accident

or serious incident

Initiation of investigation

Fact-finding investigation

・Appointment of investigator-in-charge and other investigators

・Coordination with relevant authorities, etc.

Examination, test and analysis

Deliberation by the Board

(Committee)

Deliberation and adoption by

the Board (Committee)

Submission of investigation

report to the Minister of Land,

Infrastructure, Transport and

Tourism

Publication

【Recommendations or expression of opinions, if necessary】

Follow-up onrecommendations,

opinions, etc.

【Hearings, if necessary】

The Minister of Land, Infrastructure,Transport and Tourism and parties relevantto the causes of the accident or seriousincident involved implement measures forimprovement and notify or report these to theJTSB.

Occurrence of railway accident

or serious incident

NoticeNotice

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48

3 Statistics for the investigations of railway accidents and serious incidents

In 2013, the JTSB carried out investigations of railway accidents and serious incidents. The

results are as follows. 23 accident investigations had been carried over from 2012, and 15 accident

investigations were newly launched in 2013. 17 investigation reports were published in 2013, and 21

accident investigations were carried over to 2014.

Six railway serious incident investigations had been carried over from 2012, and two railway serious

incident investigations were newly launched in 2013. Three investigation reports were published in

2013, and five railway serious incident investigations were carried over to 2014.

Of 20 published investigation reports, three were issued with recommendations.

Investigations of railway accidents and railway serious incidents in 2013

(Cases)

Category

Carried

over

from

2012

Launched

in 2013Total

Published

investigation

report

(Recom

mendati

ons)

(Opinions) (Remarks)

Carried

over to

2014

(Interim

reports)

Railway

accidents23 15 38 17 (2) (0) (0) 21 (0)

Railway

serious

incidents

6 2 8 3 (1) (0) (0) 5 (0)

4 Statistics for investigations launched in 2013

The railway accidents and railway serious incidents that were newly investigated in

2013 consisted of 15 railway accidents (down by five from the last year associated with 20

accidents) and two railway serious incidents (down by three from the last year associated

with five incidents).

The breakdown by accident categories shows that the railway accidents are comprised

of 11 train derailments, one train fire, one level crossing accident, one other accident with

casualties, and one vehicle derailment. The railway serious incidents comprised of two

dangerous troubles in vehicle.

57


The number of casualties was 40 across the 15

injured persons.

The number of casualties (in railway accidents)

Category

Crew Passenger

Casualties 0

Total

5 Summaries of railway accidents and serious incidents that occurred in 2013

The railway accidents and railway serious incidents that occurred in 2013 are summarized as follows.

The summaries are based on the information

change depending on the course of investigations and deliberations.

(Railway accidents)

No.

Date and

accident type

1 February 4, 2013

Train fire

2

0

Seriousrailway

incidents(2 cases)

Railwayaccidents(15 cases)

Number of railway accidents and serious incidents by type

Train derailment

Level crossing accident

Vehicle derailment

Chapter 3 Railway accident and serious incident investigation


49

The number of casualties was 40 across the 15 accidents. These consisted of one death and 39

The number of casualties (in railway accidents)

2013

Dead Injured

Passenger Others Crew Passenger Others

0 1 1 32

1 39



The summaries are based on the information available at the start of the investigations, and therefore may

change depending on the course of investigations and deliberations.

Operator and

line section

(location)

Summary

East Japan Railway

Company

Between Tsukuda Station

and Iwamoto Station, Joetsu

Line

(Gunma Prefecture)

While the train was running, the driver of the

train felt a shock as if the cars were being

pulled. He looked behind and noticed a fire

from a car. He then stopped the train with the

emergency brake.

He was the only one in the train and he was

not injured.

11 1 1 1 1

5 10 15


Train fire

Level crossing accident Other accident with casualties

Vehicle derailment Dangerous trouble in vehicle


accidents. These consisted of one death and 39

(Persons)

Total

Others

640



available at the start of the investigations, and therefore may

Summary


train felt a shock as if the cars were being

pulled. He looked behind and noticed a fire

hen stopped the train with the

He was the only one in the train and he was

20


Other accident with casualties

Dangerous trouble in vehicle

(cases)

58



50

2 February 8, 2013

Train derailment

East Japan Railway

Company

Between Shimokita Station

and Ominato Station,

Ominato Line

(Aomori Prefecture)

When the train was traveling near the

Sanbonmatsu level crossing at about 60 km/h,

the driver of the train sensed a shock. He then

applied the brake to stop the train. He checked

and found out the both of the axles in the front

bogie of the first car had become derailed to

the left.

Out of the 11 passengers, the driver, and a

track maintenance worker on board, no one

died or was injured.

3 February 12, 2013

Train derailment

(due to a level crossing

accident)

Sanyo Electric Railway Co.,

Ltd.

Between Iho Station and

Arai Station, Main Line

(Hyogo Prefecture)

While the train was running at about 95 km/h,

the driver of the train noticed an obstacle at

the Shinko Mae level crossing. The driver

applied the emergency brake to stop the train.

However, it was too late to avoid the collision

with the car transportation vehicle.

Out of the 50 to 60 passengers, the driver and

the conductor on board, 15 people (13

passengers, the driver, and the automobile

driver) were injured.

4 February 13, 2013

Other accidents with casualties

Keio Corporation

Between Musashinodai

Station and Tobitakyu

Station, Keio Line

(Tokyo)

While traveling along the left column section,

the train hit a worker who was removing

signal cables.

The worker was died.

5 March 2, 2013

Train derailment

East Japan Railway

Company

Between Jinguji Station and

Kariwano Station, Ou Line

(Akita Prefecture)


train noticed an unusual sound. He stopped to

check, and found out that both of the axles in

the front bogie of the first car had become

derailed.

None of the 130 passengers and crew

members were injured.

6 April 6, 2013

Train derailment

East Japan Railway

Company

Between Myoko-kogen

Station and Sekiyama

Station, Shin-etsu Line

(Niigata Prefecture)

While coasting operation at about 65 km/h,

the driver of the train felt that the train cars

were rising up. The driver applied the

emergency brake to stop the train. A survey of

the train cars revealed that both of the axles in

the front bogie of the first car had become

derailed to the right.

Out of the 25 passengers and two crew

members on board, no one was injured.

7 April 7, 2013

Train derailment

(due to a level crossing

accident)

East Japan Railway

Company

On the premises of

Chigasaki Station, Tokaido

Line

(Kanagawa Prefecture)

The train collided with an automobile at the

Jukkenzaka yard crossing in the premises of

Chigasaki Station. Both axles in the front

boogie of the first car were derailed.

Out of the approximately 300 passengers and

two crew members on board, one passenger

were slightly injured. However, none of the

three persons in the automobile were injured.

8 May 28, 2013

Train derailment

Kobe Electric Railway Co.,

Ltd.

On the premises of

Arimaguchi Station, Sanda

Line

(Hyogo Prefecture)

The driver of the train initially felt a shock

when the train left from Arimaguchi Station.

He applied the brake to stop the train. A

survey revealed that both of the axles in the

front bogie of the second car had become


Out of the 60 passengers and the driver on

board, no one was injured.

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51

9 July 31, 2013

Vehicle derailment

Nagasaki Electric Tramway

Co., Ltd.

Between Tsukimachi stop and

Shimin Byoin Mae stop, Oura

Branch Line

(Nagasaki Prefecture)

The driver of the tram noticed a bus 10 m in

front. It was on a regular route coming from

the left into the car-track lane at the

intersection. The driver applied the

emergency brake. However, it was too late to

avoid colliding with the right side of the bus.

60 passengers and the driver were in the car,

and six passengers and the driver were in the

bus. 13 of the passengers in the car and five of

the passengers in the bus were injured.

10 August 17, 2013

Train derailment

Japan Freight Railway

Company

Between Yakumo Station and

Yamakoshi Station, Hakodate

Line

(Hokkaido Prefecture)

The driver of the train noticed an obstacle in

front and applied the emergency brake. After

collision with the obstacle, he activated the

one-touch operative emergency device, since

the train appeared to be sinking. This was then

followed by another impact from the upthrow.

Both of the axles in the middle bogie of first

car were derailed, as well as the second axles

in the front bogie of the third and fourth cars.

The second axle in the front bogie of the fifth

car was also derailed from above the rail. The

driver was on board. However, he was not

injured.

11 September 17, 2013

Train derailment

East Japan Railway

Company

On the premises of Sagamiko

Station, Chuo Line


While the driver of the train was applying the

brake to stop at Sagamiko Station, an

automatic alarm started ringing when the train

was running in several meters before the stop

position. He then applied the emergency brake

to stop the train.

Out of the approximately 100 passengers and

three crew members, no one was injured.

12 September 19, 2013

Train derailment


Company

On the premises of Onuma

Station, Hakodate Line


The driver of the train, sensing an abnormal

feeling as if the cars were being pulled,

applied the brake to stop the train. A survey

revealed that both of the axles in the rear

bogie of the sixth car, both of the axles in the

front bogie of the seventh car, all four axles in

the eighth car, and both of the axles in the

front bogies of the ninth car had become

derailed.

The driver was the only one work on the train

and was not injured.

13 November 5, 2013

Level crossing accident

Kyushu Railway Company

On the premises of Takahashi

Station, Sasebo Line

(Saga Prefecture)

While running at about 50 km/h, the driver of

the train noticed an obstacle at the level

crossing in front and applied the emergency

brake. However, it was too late to avoid a

collision with the iron plates protruding from

the loading platform of a trailer.

Out of the 60 to 70 passengers and the driver

on board, five passengers were injured.

14 November 24, 2013

Train derailment

Oigawa Railway Co., Ltd.

On the premises of Igawa

Station, Igawa Line

(Shizuoka Prefecture)

The driver of the train heard an unusual sound

while entering Igawa Station and stopped the

train. A survey revealed that all of the axles in

font bogie of first car were derailed.

Out of the approximately 80 passengers, the

driver, and the two conductors on board, no

one was injured.

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52

15 December 28, 2013

Train derailment

Isumi Railway Company

Between Nishihata Station

and Kazusa-nakano Station,

Isumi Line

(Chiba Prefecture)

The driver of the train noticed some unusual

sound during operation and stopped the train

to investigate. The driver found out that the

first axle in the front bogie has become

derailed.

Out of the four passengers and the driver on


(Railway serious incidents)

No.Date and

incident type

Operator and

line section

(location)

Summary

1 January 7, 2013


Hokkaido Railway Company

Between Tsunetoyo Signal

Station and Kamiatsunai

Station, Nemuro Line


While driving at about 90 km/h, the door-pilot

lamp went out. As a result, the driver of the

train applied the emergency break to stop the

train. A survey revealed that the door on the

right side of the fifth car was open by about

30 cm.

Out of the 37 passengers and two crew


2 July 6, 2013


Hokkaido Railway Company

On the premises of Yamasaki

Station, Hakodate Line


While driving at about 130 km/h through the

premises of Yamasaki Station, the driver of

the train stopped the train after finding that

the indicator for the engine operating status

had turned off. The crew members noticed

smoke coming out from beneath the fourth

car. They used fire extinguishers to extinguish

the fire.

Out of the 200 passengers and four crew


6 Publication of investigation reports

The number of investigation reports of railway accidents and serious incidents published in 2013

was 20. These consisted of 17 railway accidents and three serious incidents.

Breaking them down by category, the railway accidents contain ten train derailment accidents,

two train fire accidents, three other accidents with casualties, and two vehicle derailment accidents.

However, the serious railway incidents contain one dangerous trouble in vehicle, one violating closure

section for construction violation of a section closed for construction, and one vehicle derailment.

In the 17 accidents, the number of casualties was 161, consisting of one death and 160 injured

persons.

61


The investigation reports for railway accidents and serious incidents published in 2013 are

summarized as follows:

List of published investigation reports on railway accidents (2013)

No.Date of

publication

Date and

accident type

1 February 22,

2013

March 11, 2011

Train

derailment

10

23

0

2

4

6

8

10

12

Railway accident reports (17 cases)published in 2013

(cases)

Train

derailmentTrain fire

Other

accidentwith

casualties

Chapter 3 Railway accident and serious incident investigation


53



Operator and

line section

(location)

Summary

East Japan Railway

Company

On the premises of

Sendai Station,

Tohoku Shinkansen

Line

(Miyagi Prefecture)

While the train was entering Sendai Station at a

speed of about 72 km/h, the driver felt a strong

vibration at the same time that the stop signal

indicated in the cab signal. A

the emergency brake. A review after the stop

revealed that both of the axles in the front bogie of

the fourth car were derailed to the left.

This train was a test run, there were 12 vehicle

inspection and repair worker and one crew m

on board. However, no one was injured.

Note that immediately before the accident occurred

the 2011 Tohoku earthquake struck off the shore of

Miyagi Prefecture with a moment magnitude of 9.

This resulted in the observation of a maximum

seismic intensity of 7 in the north of Miyagi

Prefecture.

1 1

0

2

4

6

8

Dangeroustrouble in vehicle

Violating closuresection for

construction

Serious railway incident reports(three cases) published in 2013

2

Railway accident reports (17 cases)

(cases)

Vehicle

derailmentaccident

casualties




Summary

While the train was entering Sendai Station at a

speed of about 72 km/h, the driver felt a strong

vibration at the same time that the stop signal

indicated in the cab signal. As a result, he applied

the emergency brake. A review after the stop

revealed that both of the axles in the front bogie of

the fourth car were derailed to the left.

This train was a test run, there were 12 vehicle

inspection and repair worker and one crew member

on board. However, no one was injured.

Note that immediately before the accident occurred

the 2011 Tohoku earthquake struck off the shore of

Miyagi Prefecture with a moment magnitude of 9.

This resulted in the observation of a maximum

ty of 7 in the north of Miyagi

1

Violating closuresection for

construction

Vehiclederailment

Serious railway incident reports(three cases) published in 2013

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54

2 February 22,

2013

December 24,

2011

Train

derailment

SEIBU RAILWAY

Co., Ltd.

On the premises of

Higashi-Murayama

Station, Seibuen Line

(Tokyo)

After passing turnout No. 67 on the premises of

Higashi-Murayama Station at a speed of about 32

km/h into Track 5 of the station, and when the head

of the train passed the No. 66-I and RO turnouts, the

driver of the train felt as if the train was being pulled

from behind. Immediately after this situation, the

driver noticed that the door-pilot lamp in the

driver’s cab had turned off for a moment. As a

result, the driver applied the emergency brake. The

train stopped after traveling for about 21 m after

applying the brake. A survey after the stop revealed

that both of the axles in the front bogie of the

seventh car had become derailed to the right.

Of the approximately 450 passengers and two crew

members on board, no one was died or injured.

3 February 22,

2013

February 16,

2012

Train

derailment


Company

On the premises of

Higashi-Oiwake

Station, Sekisho Line


When entering Kawabata Station, the driver of the

train was instructed by the train dispatcher of

Hokkaido Railway Company that the train should

pass a downbound limited express diesel train at

Higashi-Oiwake, rather than at Kawabata Station.

As the train was about to stop at Kawabata Station,

the driver stopped briefly at the station and then

departed immediately. He applied the brake to

decrease the speed in order to stop at

Higashi-Oiwake Station. However, the train entered

into the safety siding without decreasing in speed. It

penetrated the car stop and ran into the snow shelter.

This resulted in the derailment of the first to fifth

cars of the train, which had 16 cars in total.

The only one driver was on board and was not

injured.

4 February 22,

2013

March 7, 2012

Train

derailment

Hokkaido Railway

Company

Between Hashibetsu

Station and Mashike

Station, Rumoi Line


While coasting operation at about 55 km/h, the

driver of the train noticed a pile of earth and sand

mixed with snow about 100 m ahead on the tracks.

Although he immediately applied the emergency

brake, the train ran over the pile, resulting in

derailment of all of the axles in the front bogie to the

right.

Out of the one passenger and one crew member on

board, no one was injured. The front window at the

driver’s seat and some devices under the floor,

including a snow plow, were damaged.

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55

5 March 29,

2013

June 17, 2011

Other accidents

with casualties

Nishi - Nippon

Railroad Co., Ltd.

Between Shimoori

Station and

Tofuro-mae Station,

Tenjin Omuta Line

(Fukuoka Prefecture)

While traveling in the left column section, the driver

of the train heard a bang at the same time that

overhead contact line suffered an outage. He applied

the emergency brake to stop the train. At that time,

sparks (or melted objects) scattered around the rear

part of the third car. This caused a two-year-old

passenger who was at rear right side of the car to be

hurt in the abdomen. After an inspection, the train

started operation again, but the service was ceased at

Tofuro-mae Station and deadheaded to Chikushi

Station. The cars were put into depot. After that,

damage in the roof was discovered.

30 passengers and two crew members had been on

board.

6 March 29,

2013

June 19, 2012

Train

derailment

HAKONE TOZAN

RAILWAY Co., Ltd.

Between Deyama

Signal Station and

Ohiradai Station, Trail

Line


During a powering operation at about 20 km/h after

departing from Deyama Signal Station, the driver of

the train noticed a rock between the rails seven

meters ahead. He immediately applied the

emergency brake. However, it was too late to avoid

a collision, which resulted in the derailment of the

first axle in the front bogie of the first car to the left.

11 passengers and two crew members were on

board, but there were no casualties. Some devices

below the floor, including the water tank at the front

and the foundation brake gear at the first axle of the

front bogie, were damaged.

7 April 26,

2013

February 17,

2012

Other accidents

with casualties

West Japan Railway

Company

On the premises of

Nishi-Akashi Station,

Sanyo Line

(Hyogo Prefecture)

During a powering operation on the premises of

Nishi-Akashi Station at a speed of about 106 km/h,

the driver of the train realized that a general freight

truck was traveling along the passage in front that

crosses the railway. He immediately blew the

whistle and applied the emergency brake. However,

it was too late to avoid a collision with the truck.

The train stopped at a point 404 m away from the

intersection with the passage.

Out of the 146 passengers and three crew members

on board the train, nine passengers were injured.

The driver on the truck was also injured in this

accident.

The front window glass and the coupler of the first

car, as well as the window glass on the left side of

the first to third cars were damaged, as well as other

areas. No fire occurred despite the fact that the

general freight truck was totaled.

8 May 31,

2013

May 27, 2011

Train

derailment

Hokkaido Railway

Company

On the premises of

Seifuzan Signal

Station, Sekisho Line


Refer to “7. Summaries of recommendations and

opinions” (page 67-①).

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56

9 June 28,

2013

January 4, 2012

Train fire

TOYAMA CHIHOU

TETSUDOU. INC

On the premises of

Tateyama Station,

Tateyama Line

(Toyama Prefecture)

The driver of the train moved into the driver’s cab in

the first car, which faced the direction of travel, to

prepare for departure for Dentetsu-Toyama Station.

Upon doing so he discovered a fire on the floor

around one meter behind the passenger door in the

front right side of the car. Although he used a fire

extinguisher to fight the fire, he failed to control it.

Afterward, while some seats in the car were burnt,

the firefighters extinguished the fire.

None of the five passengers and the driver on board

were injured.

10 July 26,

2013

April 4, 2012

Train fire

East Japan Railway

Company

On the premises of

Kujiranami Station,

Shin-etsu Line

(Niigata Prefecture)

While operating the train at a speed of about 20

km/h due to operation control under strong winds,

the driver of the train noticed an unusual sound, as

well as two occurrences of an outage in the overhead

contact line after coming out of the Kujiranami

Tunnel. The other drivers on board checked the rear

section and noticed flames around the pantograph at

the front section of the second car. The driver

applied the emergency brake to stop the train.

The roof and ceiling around the pantograph has

already become burnt, so they used extinguishers to

try to control the fire. However, they were unable to

control it. Afterward, firefighters arrived and

extinguished the fire.

Out of the 41 passengers and six crew members on

board, no one was died or injured.

11 July 26,

2013

June 25, 2012

Train

derailment

Shikoku Railway

Company

Between Konokawa

Station and

Iyo-Kaminada Station,

Yosan Line

(Ehime Prefecture)

While running the train in the section listed to the

left column, the train driver noticed utility poles and

piles of earth over the railway. He immediately

applied the emergency brake but it was too late. The

train ran into a mixture of sand and rocks and

stopped with all four axles derailed.

Only the driver was on board and was not injured.

Some devices at the front end under the floor of the

vehicle were damaged.

12 July 26,

2013

July 28, 2012

Train

derailment

TOYAMA CHIHOU

TETSUDOU.INC

Between Kosugi

Station and Kamihori

Station, Kamidaki

Line

(Toyama Prefecture)


opinions” (page 69-②).

13 August 30,

2013

July 24, 2012

Other accidents

with casualties

Central Japan Railway

Company

On the premises of

Higashi-Shizuoka

Station, Tokaido Line

(Shizuoka Prefecture)

During a coasting operation at a speed of about 92

km/h while making an entry into Higashi-Shizuoka

Station, the driver of the train noticed a train

watchman walking between the platform and the

right-side rail of the down line in the station

premises. He was walking in the direction of

Shizuoka Station, with his back to the train. The

driver blew the whistle and applied the service

brake. However, the watchman did not escape to the

outside of the railway. He then applied the

emergency brake, but it was too late to avoid hitting

the watchman, leading to his death.

Slight damage was discovered on the right side of

first car of the train.

Out of the 29 passengers, the driver, and a conductor

on board, no one was injured.

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57

14 September

27, 2013

June 11, 2012

Vehicle

derailment

(caused by

trouble with

road traffic)

OKAYAMA

ELECTRIC

TRAMWAY Co Ltd.

Between Kencho-dori

stop and Saidaiji-cho

stop, Higashiyama

Main Line

(Okayama Prefecture)

In the section from the Kencho-dori stop toward the

Saidaiji-cho stop, the driver made the tram coasting

operation at about 30 km/h. The driver of the tram

noticed a automobile coming into the tram tracks

from the opposite lane so that it could turn right at

the intersection. The automobile was about ten

meters in front of the tram. Although the tram driver

immediately applied the emergency brake, the

electric tram collided with the automobile, went

through the intersection, and stopped at a point

about 20 m ahead in a derailed state. The automobile

collided with a utility pole and stopped.

Out of the 71 passengers and the driver on board the

tram, eight passengers were injured. The only one

driver was in the automobile and was not injured.

15 September

27, 2013

September 15,

2012

Vehicle

derailment

(caused by

trouble with

road traffic)

Tosa Electric Railway

Co., Ltd.

Between Nagasaki

stop and Kogome-dori

stop, Gomen Line

(Kochi Prefecture)

During a powering operation through the line along

National Route (NR) 195 at a speed of about 30

km/h, the train driver noticed a general freight

hauler with a large trailer coming into the

intersection of NR 195 and NR 32 from the left. This

occurred within the section described in the left

column. He immediately blew the whistle and

applied the emergency brake. However, it collided

with the hauler. The train was stopped and was


Out of the ten passengers and the driver on board,

four of the passengers and the driver were injured. A

driver on the general hauler was also injured.

The train suffered damages to the windows at the

front and in the passenger room. The hauler also

suffered damages to the front and right side surface

of the body. No fire happened in the general freight

hauler.

16 September

27, 2013

September 24,

2012

Train

derailment

Keikyu Corporation

Between Oppama

Station and Keikyu

Taura Station, Main

Line


During a coasting operation at about 72 km/h, the

driver of the train noticed a pile of earth and sand on

the tracks 30-40 meters ahead. He immediately

applied the emergency brake, but it was too late to

avoid running into the pile of sand. The train

stopped after traveling a further 84 m. All the four

axles in the first car, both of the axles in the front

bogie of the second car, and both of axles in the

front bogie of the third car were derailed to the right.

When the train stopped, the part of the train from

first car to the middle of fourth car was in the

Funakoshi Daiichi Tunnel.

Out of the approximately 700 passengers and two

crew members on board, 55 passengers and the

driver were injured.

17 December

20, 2013

December 15,

2012

Train

derailment

Kyushu Railway

Company

Between Setoishi

Station and Kaiji

Station, Hisatsu Line

(Kumamoto

Prefecture)

After the train went out of the Koudabe Tunnel and

went through a right curve, the driver noticed a large

rock about 30 m ahead on the tracks. Although he

immediately applied the emergency brake, it was too

late to avoid the collision with the rock before

stopping. A check by the driver revealed that the

second axle in the front bogie of the second car had

become derailed to the left.

Out of the 45 passengers and two crew members on


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58

List of published investigation reports on serious railway incidents (2013)

No.Date of

publication

Date and

incident type

Operator and

line section

(location)

Summary

1 October 25,

2013

June 27, 2012

Vehicle derailment

Sangi Railway Co.,

Ltd.

On the premises of

Higashi-Fujiwara

Station, Sangi Line

(Mie Prefecture)


opinions” (page 70-③).

2 November

29, 2013

August 9, 2011

Dangerous trouble in

vehicle

Tenryu Hamanako

Railroad Co., Ltd.

Between

Hamamatsu

Daigaku Mae

Station and

Miyakoda Station,

Tenryu Hamanako

Line

(Shizuoka

Prefecture)

While applying the brake to stop at Miyakoda

Station, the driver of the train used the brake

handle to stop the train immediately after the

passenger door in the front right section of the car

opened. A survey after the stop revealed that the

passenger door in the front right section of the car

was fully open, and the passengers were coming

into the train through the passenger door at the

rear right side. Afterward, in accordance with the

instructions from the operation dispatcher, the

train was operated with the door that had been

experiencing problems locked. The vehicle was

exchanged for another one at Tenryu Futamata

Station.

There were dozens of passengers on the train, but

no one was injured due to falling.

3 December

20, 2013

July 13, 2012

Violating closure

section for

construction

East Japan Railway

Company

On the premises of

Takasaki Station,

Takasaki Line

(Gunma Prefecture)

The assistant stationmaster of Takasaki Station

received an application to approve the launch of

construction to close the railway for the up and

down lines. This application was left from the

construction manager. After confirming that the up

line train in the Joetsu Line had departed from the

section to be closed, he approved the launch.

A down line train from Takasaki to Yokokawa of

Shin-etsu Line departed from Track No. 6 on time,

and made its way into the section to be closed after

the approval.

7 Summaries of recommendations and opinions

The recommendations and opinions issued in 2013 were summarized below:

① Hokkaido Railway Company: Train derailment accident on the premises of Seifuzan Signal

Station in the Sekisho Line

(Recommendation issued on May 31, 2013)

○ Summary of the accident

On May 27, 2011, an up line train of six cars, from Kushiro Station to Sapporo Station,

operated by Hokkaido Railway Company, departed from Tomamu Station two minutes behind

schedule.

While the train was running toward Seifuzan Signal Station, the conductor at the conductor’s

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59

cabin in the fourth car noticed unusual sounds and vibrations. As a result, the conductor notified the

driver of the event. The driver immediately made arrangements to stop the train. It was in the

Dai-ichi Niniu Tunnel on the premises of the signal station.

Smoke from a fire that broke out in one of the cars then came flying inside the other cars. The

driver tried to move the train out of the tunnel, but the train would no longer start.

There were 248 passengers, the driver, the conductor and two cabin attendants on board train.

All of them escaped out of the tunnel on foot. 78 passengers and the conductor were injured.

The first axle in the rear bogie of the fifth car was derailed to the left. One of the transmissions

of the train in the rear of the fourth car was damaged. The components of the broken transmission

were scattered around the line from 2 km back from the place that the train stopped. The fire burnt all

the six cars of the train.

○ Probable Causes

In this accident, the falling off of the hanger pin for the reduction gear at the rear of fourth car

was considered to be the cause of both the axles in the rear bogie of the fourth car, as well as the first

axle in the rear bogie of the fifth car, becoming derailed. It is though that events proceeded as

follows:

(1) The reduction gear was hanging down around the axle and facing frontward. The propeller

shaft was also hanging down at a later stage. These factors resulted in damage to an universal

joint and separation of the reducer gear and the propeller shaft.

(2) After the separation, the hanging part of the rotating reducer gear came into contact with one

of the 12-RO turnout’s lead rail while on the premises of Seifuzan Signal Station. This contact

pushed the rear bogie of the fourth car to the left along the rail, causing the first axle and then

the second axle to be derailed. The two axles then returned back to the line at the 11-I turnout.

(3) The bevel gears fell off from the hanged reduction gear and into the gauge. The rear bogie

of the fifth car came in contact with the bevel gears. This caused the bogie to be pushed up,

forcing the first axle to become derailed.

It is thought that the hanger pin for the reduction gear fell off in the following procedure of

events. In terms of the cause, it is considered that the irregular circular shape of the left wheel of the

first axle in the rear bogie of the fourth car played a role in the occurrence of the large vibration.

(1) The split pins of fluted hex nuts on the hanger pins for the reduction gear and cotter pins on

the upper part of the hanger pins suffered a local abrasion due to contact with the other

components.

(2) The loosened fluted hex nuts imposed a repetitive load on the split pins, resulting in them

falling off.

(3) The fluted hex nuts then loosened even further and fell off.

(4) The cotter pins on the upper part of the hanger pins for the reduction gear fell off due to the

repetitive load received from the hanger pins.

(5) After fluted hex nuts and cotter pins fell off, the hanger pins for the reduction gear also fell

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60

from the prop stick of the reduction gear.

The cause of the cars of the train being burnt in this accident is considered to be the damage to

the fuel tank at the front of the sixth car. This was caused by the fallen bevel gear of the reduction,

which leaked light oil that scattered around the wooden railroad ties. A fire then broke out near the

generator or the rear upper edge surface of the engine and spread to a wider area.

A overhaul analysis of the devices under the floor, which suffered considerable damage from

the fire, as well as of the devices that generated heat during the operation, revealed that all of them

were burnt by an external source. It was therefore impossible to identify the precise point that the fire

broke out or its cause.

○ Description of the recommendation to Hokkaido Railway Company

Hokkaido Railway Company should establish proper plans and processes for inspection and

thoroughly manage the state of the wheel treads. This is to prevent the use of wheels that have too

much abrasion on their tread or too long peels.

② Toyama Chihou Tetsudou, Inc.: Train derailment accident between Kosugi Station and

Kamihori Station, Kamidaki Line

(Recommendation issued on July 26, 2013)

○ Summary of the accident

On July 28 2012, a driver was operating a Toyama Chihou Tetsudou No. 624 two-car local

train from Iwakuraji Station to Dentetsu-Toyama Station. On the way, he noticed unusual sounds and

shocks when stopping at Kamihori Station. He then applied the emergency brake to immediately stop

the train. A check after the train stopped revealed that all eight of the axles were derailed.

There were 20 passengers and the driver on board the train. No one was injured.

○ Probable Causes

In our opinion, at the outlet-side transition curve of the left-hand curve, which is followed by a

reverse right-hand curve, the lateral displacement of the track (track irregularity) was larger than

allowed under the maintenance criteria and decreased the fastening force of the rail fastening system.

This caused the lateral force associated with the running of the train to extend the gauge, leading the

left wheel inside the rail to derail to the right.

The causes of these are considered to be:

(1) The looseness of the bolts of the line’s rail fastening system, which was caused by repetitive

lateral force of trains. This had not been modified since the rail had been replaced two months

before the accident.

(2) The excessive shifting of track that had not been modified. However the track irregularity

was larger than allowed under the criteria for maintenance at the time of rail replacement, the

rails had been in use with this situation not being addressed. Also, the result of a regular

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61

inspection on the shifting of track after the rail replacement had remained unanalyzed.

○ Description of the recommendation to Toyama Chihou Tetsudou, Inc.

(1) Toyama Chihou Tetsudou, Inc. (TCT) should establish a solid management system for the

maintenance of tracks. Within this system, the measurement results for the shifting of track

should be analyzed and evaluated immediately after measurement. Any problems should be

quickly resolved in accordance with an established repair plan.

(2) TCT should not only develop a detailed implementation plan regarding the following items,

with the active involvement of its business administrations, including its safety management

committee, but also properly manage the implementation status of such a plan.

① All the items of the preventive measures defined by TCT in response to the train

derailment accident occurred on the premises of Nakakazumi Station in 2008.

② Thorough checks after working on the tracks and management of a fastening system for

PC rail ties, as well as the management system for the maintenance of tracks that was

developed in (1).

③ Sangi Railway Co., Ltd.: Serious railway incident on the premises of Higashi-Fujiwara Station

on the Sangi Line

(Recommendation issued on October 25, 2013)

○ Summary of the serious incident

At about 3:00 P.M. on June 27 2012, one of Sangi Railway Co., Ltd.’s 18-car shunting train

(two electric locomotives and 16 freight cars) sets started from the private siding of a cement factory

for the downbound main line in Higashi-Fujiwara Station.

The driver of the train set, noticing an abnormal condition when it was passing the

Higashi-Fujiwara No. 13-I turnout, immediately applied the emergency brake to stop the train. The

first axle in the front bogie of the second locomotive was derailed to the right.

A driver was working in the second locomotive, and two guides were in the first one, as well as

a switchman in the third one. None of them were injured.

○ Probable Causes

This serious incident occurred when the set of 18-car shunting train (two electric locomotives

and 16 freight cars) was running along the section of the base line side of a turnout that goes in the

same direction as the curve. The turnout was in a section that contained four consecutive curves. The

situation was attributable to an increase in the derailment coefficient, which occurred at the same

time as a decrease in the threshold derailment coefficient. As a result, the right wheel in the first axle

of the second locomotive’s front bogie subsequently ran up the outside rail and derailed to the right.

The increase in the derailment coefficient is considered to be a result of the increase in lateral

force, as well as a decrease in the wheel weight. This situation can be deduced from the following

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62

factors: the track was deformed in a direction that results in the reduction of the radius; the twist of

the track increased so that the train leaned to the front right, and; it is assumed that the train was

running with excess of cant, which was due to its low-speed. The shift of the axle load due to the

power running at an ascent can also be considered as a factor.

The decrease in the threshold derailment coefficient is considered to result from a shifting of

track, which is associated with an excessive reduction of the radius, resulting in an increase in the

angle of attack for the first axle of the front bogie.

The rapid shifting of track and the increase in twists may have resulted from their poor

management of the shapes and shifts of the tracks. They did not understand the specification of plain

curves, or did not inspect the shifts of the tracks in the turnouts. As a result, they were not able to

recognize that the state of the tracks exceeded the allowances of its maintenance criteria.

○ Description of the recommendation to Sangi Railway Co., Ltd.

Sangi Railway Co., Ltd. should make sure that their tracks are well maintained. They should do

so by grasping the design values for maintenance and management and by inspecting shifts properly

in accordance with the “Practice Criteria for construction works” in sections involving curves and/or

turnouts.

8 Actions taken in response to recommendations in 2013

Actions taken in response to recommendations were reported with regard to one railway

accident and one serious railway incident in 2013. Summaries of these reports are as follows.

① Hokkaido Railway Company: Serious railway incident on the premises of Oiwake Station,

Sekisho Line (dangerous damage in facilities)

(Recommendation issued on November 30, 2012)

On November 30, 2012, the Japan Transport Safety Board (JTSB) published an investigation

report and issued a recommendation to Hokkaido Railway Company, parties concerned, regarding the

serious railway incidents that occurred on the premises of Oiwake Station in Sekisho Line between

June 14 and June 16, 2011. JTSB then received the following report regarding the measures

(implementation plans) to be taken based on the recommendation.

○ Summary of the serious incident

First incident:

On June 14 2011, one of Hokkaido Railway Company’s westbound one-car local trains from

Oiwake Station to Sapporo Station departed from Track No. 1 at Oiwake Station on time.

A signaler at the station’s signal cabin noticed that even though the train departed from Track

No. 1, the indicator of the track’s starting signal did not light off on the indicator panel to provide an

indication to stop. Instead, it stayed lit-up in green. The sequence recorder of the interlocking device

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63

stated that the starting signal did not indicate a red stop light at the time.

Second incident:

On June 14 2011, a westbound four-car local train from Sapporo to Obihiro departed from

Track No. 1 in Oiwake Station on time.

The same signaler involved in the first incident noticed that even though the train departed

from Track No. 1, the indicator for the track’s starting signal did not light off on the indicator panel

to provide an indication to stop. Instead, it stayed lit-up in green. The sequence recorder of the

interlocking device stated that the starting signal did not indicate a red stop light at the time.

Third incident:

On June 15 2011, a westbound five-car local train from Sapporo to Obihiro departed from

Track No. 1 in Oiwake Station on time.

A different signaler from the one involving the first and second incidents noticed that even

though the train departed from Track No. 1, the indicator for the track’s starting signal did not light

off on the indicator panel to provide an indication to stop. Instead, it stayed lit-up in green. A

construction worker also confirmed that the starting signal did not indicate the stop signal.

Fourth incident:

On June 16 2011, a westbound one-car local train from Chitose to Yubari departed from Track

No. 4 in Oiwake Station two minutes behind the schedule.

A staff other than the ones involved in the first to third incidents noticed that even though the

train departed from Track No. 4, the indicator for the track’s starting signal did not light off on the

indicator panel to provide an indication to stop. Instead, it stayed lit-up in green. The sequence

recorder of the interlocking device stated that the starting signal did not indicate a red stop light at

that time.

○ Probable Causes

This serious incident can be attributed to an incorrect circuit being made during the

improvement work for the future implementation of CTC and PRC. In the circuit, the signal control

relay for the starting signals received a feedback current when the westbound starting signals for

Sekisho and Muroran lines were set up at the same time. Therefore, it is likely that every time a train

reached the westbound starting signal for the Sekisho Line, the signal did not change from the

proceed to stop indication.

In its wiring operation:

(1) No switching plugs were used to connect the anodes of the new relays to the existing

facilities.

(2) The cathodes of the new relays were connected each other.

(3) New relays had been inserted into the relay rack.

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64

Therefore, if the routes for Sekisho Line and for Muroran Line were set up at the same time, a

circuit passing the cathodes of the interconnected new relays would be generated. This would result

in the current flowing back into the signal control relay that corresponds to the configured route.

These likely to related to:

(1) Non-compliance with the provisions of its office regulation, which require a switching plug

to be inserted into both the anodes and cathodes of the existing facilities when using a

switching plug to improve these facilities.

(2) A lack of adherence to the rule that any wiring work to existing facilities that in any way

improves an interlocking device as a signaling system should be regarded as having the

possibility of influencing the operation of trains.

(3) The absence of a prior check for the portions related to wiring by using wiring diagrams

showing the switching plugs. This was the case even though the electric connection diagrams

were double-checked.

(4) The wiring was conducted before the wiring diagram had been approved.

(5) Improper progress management for the wiring.

It is possible that the absence of a prior check for the wiring diagrams of the portions was

attributable to the situation where both the supervisor and the subcontractor of the wiring were busy

with other construction work. This resulted in the omission of a large part of the prior check.

In this case, similar incidents occurred many times. The reasons for thinking this are because:

a) even though the signal was not operating correctly (it did not indicate a stop light when it should

have), it was not regarded as an incident, b) no emergency contact system was launched, and c) staff

members did not properly take over their jobs.

○ Description of the recommendation to Hokkaido Railway Company

(1) Hokkaido Railway Company has defined its preventive measures as being: a) the need to

develop a procedure for construction in order to avoid influences on the existing signaling

system, including checks for the position of inserted switching plugs and checks for various

drawings. As well as, b) the need for the operation manual to describe some of the measures to

be taken when a signaler recognizes an event where a signal that should indicate a stop signal

is not lighting off properly. These measures are considered effective for the prevention of

reoccurrence. However, it is essential to continuously educate the company’s employees so

that they fully understand the point of these measures and take appropriate measures against

any abnormal situations.

(2) The company also experienced a serious incident on the Hakodate Line on January 15, 2009

where a block signal that should have indicated a stop light did not so. This serious incident

occurred despite the fact that some of the preventive measures had already been taken after the

former incident. Considering this, the company should re-inspect the system for construction

and the measurement methods, and train everyone engaged in construction, including outside

partners, so that they can acquire the basic operations for construction related to signaling

equipment. By doing so, they should discuss safety measures and take all necessary measures

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to prevent any more serious events.

○ Measures to be taken based on the recommendation (implementation plan)

I. Ask for that preventive measures be understood and undertake continuous training of employees

1 Measures already taken

After this serious incident, we have taken the following four measures to prevent similar

accidents relating to signal wiring:

① When using plug jacks, make sure to disconnect both sides of the wiring so as to avoid

wiring to existing facilities while the lines active.

② So as to avoid making a circuit flowing current back into the circuit through relays, no relay

should be inserted until the launch of the renewed facility, except for test runs.

③ The wiring of active lines to existing circuits should be treated as a task that can influence

the operation of trains. This task should therefore be done only after a temporary stopping

procedures for operating equipment.

④ In order to prevent errors in wiring, make sure to use approved drawings. Also make sure to

hold a meeting between the supervisor and subcontractors to discuss in detail the specifics of

the wiring, necessary procedures, and the impacts on existing facilities. Use the diagrams while

doing so. Furthermore, make sure to control the progress of the wiring.

In addition, an instruction for station staff has been added to its station operation manual. It

states that if they notice any false signal in the control panel or the display panel, they must

force all the signals to indicate stop, as well as notify the train dispatcher and related manager

of electric facilities of the event.

2 Measures to be taken later

Continuously conduct the educational training shown in (1) to (3) below, which relates to the

purposes of the preventive measures.

(1) Educational training for those engaging in signal work

① For employees engaging in work on the signaling system, the following content should

be added in the annual education curriculum developed in the electricity plan division, so

that educational training can continue:

i. In the safety training for employees working with electricity, which is performed

every year for all employees engaging in work with signaling system, the preventive

measures should be taught.

ii. Every year after 2012, a joint education on interlocking devices and wiring should be

performed for those who are engaging in the change of interlocking devices. Preventive

measures are also taught for this area.

iii. Every year after 2012, we should perform practical trainings relating to the approval

of drawings and wiring work, including hands-on training for wiring in training

facilities. This is so we can enable anyone to perform wiring work in accordance to the

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rules for wiring.

iv. Preventive measures should be taught in the on-site training for signaling protective

systems (e.g., level crossing protective devices). These should be guided by the staff of

the electricity planning division from 2012.

② Continuously train staff from any subcontractor in accordance with the following

content:

i. In the education for those engaging in tasks directly related to the operation of trains,

which is conducted every year by the electricity planning division, lectures on the

preventive measures should be added to the curriculum for those engaging in the

construction of signaling system.

ii. In the lecture about the qualifications that signal work technicians are required to

finish once every three years, lectures on the preventive measures should be added to

the curriculum.

iii. The purposes for the preventive measures should be added to the training materials

produced by the subcontractors. The electricity planning divisions should check the

achievement of the subcontractor’s training for preventive measures. They should do so

by looking at the achievement records.

③ Continued achievement of the education shown in ① and ② should be explicitly

stated in our operation manual for construction of the train protection system.

(2) Education and training for station attendants

The following education about operations should be achieved for the station attendants so

that they can take preventive measures as well as operation suspension arrangements. This is

necessary in case they are forced to stop trains due to an accident or any related risks.

① The station operation manual and other materials should be used for the in-house

training for existing station attendants and for the training for new signalers at each

station. It should be used to teach detailed operations, such as the structure of automatic

blocks and how to use the interlocking devices, as well as how to respond to failures in an

interlocking device. The station planning division should make sure it is aware of the

staff’s degree of understanding and the educational records.

Furthermore, the station planning division should draft a guideline for the education of

the station staff that specifies detailed steps, such as the structure of automatic blocks and

how to use the interlocking devices, as well as how to respond to failures in an

interlocking device.

② The station planning division should add how to respond to failures in an interlocking

device to the curricula for the general training for station masters, signalers, and transport

officers. The station planning division should grasp the degree of understanding through

end-of-course examinations.

(3) Education and training for dispatchers

The example of this set of serious incidents should be added to the case studies of

incidents taught in the in-house education. This will ensure that the trainees understand that

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when they notice false signals in the display panel, or are notified of false signals in the

station, they should set up all the related signals in the station yard to stop and notify the

signal and communication dispatchers to inspect the facilities. To continue the education,

our guideline for education and training for dispatchers should explicitly state that this item

should be taught at least once a year.

II. Safety measures for construction of the signaling system


After this serious incident, the measures of ① to ③ have already been taken as preventive

measures:

① To reinforce the construction management systems, we have defined a rule that staff

members at our construction technology center, which is in charge of design, should

supervise constructions that change the actions of interlocking devices.

② In order to avoid mistakes or leaked items in the wiring diagram and test checklist for

interlocking devices, a dedicated checker should be assigned to the electricity planning

division to check wiring diagrams and test checklists. This should be done in addition to the

conventional checks made by the Construction Technology Center, which is in charge of the

supervision and electricity offices responsible for field construction. The reason for this is to

reinforce the management system of drawings.

③ Before the launch of new or improved interlocking devices, a launch meeting should be

held consisting of a selection of responsible staff. We have thus established a system of

mutual checks for in-house examinations and construction structures.


The electricity planning division should refer to examples of wiring used by other companies

and conduct the following rechecks:

(1) Education and training have been undertaken for those engaging in the construction of

signaling systems in the curriculum stated above in section I, such as for preventing serious

incidents like this one. However, in addition to this, the staff members of the electricity

planning division should also visit the office of the contractor to recheck whether the

defined rules are being correctly performed regarding the quality management of documents

and the progress for the wiring work. This includes checks for applied drawings, procedures

of approval and adherence to the rules.

(2) We should recheck for discrepancies in the related regulations or insufficient content in

the preventive measures for case studies of past accidents.

(3) We should immediately take safety measures against any problems identified in the

checks stated above in (1) and (2). We should also teach these problems in the education

stated above in I if necessary.

Based on the results of the checks the following actions should be taken. Firstly, the field

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manager for construction should continuously check whether the defined rules and basic

operations are being adhered to. Secondly, the electricity planning division should regularly

inspect the items in (1), as well as the performance of safety checks. Thirdly, any problems

that need to be corrected should be taught and instructed in a way that allows the workers to

acquire the skills for basic operations as soon as they are identified. To realize these actions,

standardize the inspection methods for safety checks and countermeasures in regards to

problems and results.

* The implementation plan is available on the board’s website:

http://www.mlit.go.jp/jtsb/railkankoku/railway-kankoku2re-1_20130220.pdf

② Hokkaido Railway Company: Train Accident on the premises of Seifuzan Signal Station in the

Sekisho Line

(Recommendation issued on May 31, 2013)

On May 31 2013, the Japan Transport Safety Board (JTSB) published an investigation report

and issued a recommendation to Hokkaido Railway Company, who was responsible for the accident.

The report and recommendation were in regards the train accident that occurred on the premises of

Seifuzan Signal Station in the Sekisho Line, which was managed by the company, on May 27 2011.

The JTSB then received the following report regarding the measures (implementation plans) to be

taken based on the recommendation.

○ Refer to “7. Summaries of recommendations and opinions (page 67-①)” for the overview, cause,

and recommendation for the accident.

○ Measures to be taken based on the recommendation (implementation plan)


Our vehicle planning division has already taken the following measures to strictly manage the

states of wheels and tread surfaces:

(1) Continuous sets of detachments on the tread (detachments from abrasion or from heat

cracks) are treated as single detachments. Daily inspections and regular inspections

include checks for the state of the wheel treads, including checks for continuous

detachments. If the inspection results reveal that the allowable criteria has been exceeded,

operations are immediately stopped so that the wheels can be turned or replaced. These

measures are to be detailed in the corporate regulation, which states the purpose of

establishing a system of continuous inspections.

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(2) It was decided in a meeting of wheel inspection managers that all the field staff must be

instructed to observe the rule described in (1), in addition to the conventional criteria.

(3) We held a technical session for field managers and wheel management staff to educate

them on the importance of wheel management and distinguishing unavailable wheels. We

did so by reviewing actual wheels that had been damaged and lectures from wheel

manufacturers.

(4) We drafted a document to help educate the wheel managers, and use this to reeducate

the wheel management staff and daily inspection staff, as well.

(5) We held a new integrated training, known as the “Wheel Management Course.” This

was held in order to teach wheel management to the wheel management staff and daily

inspection staff. This training should be stated in the Educational Guidance (annual

education plan) and be held regularly.

(6) We delivered samples of wheels that contained detachments to the six places where

vehicles are arranged. We did so to teach about heat cracks and wheel detachments to the

wheel management staff and daily inspection staff.

(7) We determined that the interval of wheel turning, as an indication of car mileage, for

the 283 Series diesel railcars is 100,000 km in the summer and 80,000 km in the winter.

We made this standard known through the technical sessions for field managers and wheel

management staff.


To prevent similar accidents from occurring, our vehicle planning division should take the

following measures to improve quality:

2.1. Items regarding wheel inspections

(1) Establish a system to constantly check the wheels for states of abrasion and

detachment. This includes using a procedure to record any discovered abrasions or

detachments below the criteria in the inspection book, which should be inspected again in

order to understand how much the wheels have deteriorated.

(2) Staff in our vehicle planning division should visit each field twice a year to understand

the status of wheel management and wheel inspections. They should also guide and review

the inspection methods if necessary.

(3) Introduction at a system should be discussed as early as possible in order to

continuously and quantitatively detect heat cracking and abrasions (including

detachments) on the wheel. The system should be able to be executed while the train is

operating and should be able to detect issues.

2.2. Items regarding the drafting of wheel turning intervals

(1) Since “detachment through heat cracks” is gradually generated around the wheel

surface, we should investigate the relationship that it has with the vibration that occurs

while the train is in operation. We should also investigate the progress of the detachment

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over a period that covers multiple winters.

(2) Through the achievement of (1), we should try to optimize the wheel turning interval

for each type of vehicle.

(3) We should validate the necessity of reviewing conventional criteria for the length of

the tread cracks and detachments for high-speed vehicles, as well as for vehicles with

wheels that have a small diameter.

* The implementation plan is available on the board’s website:

http://www.mlit.go.jp/jtsb/railkankoku/railway-kankoku3re-1_20130809.pdf

9 Information dissemination in the process of investigations in 2013

There were no cases of information dissemination in 2013.

79

Chapter 3: Railway accident and serious incident investigation


65

10 Summaries of major railway accident and serious incident investigation reports

The seismic vibration from the main shock of the Great East Japan Earthquake forced a Shinkansen train to be derailed

Train Derailment in Sendai Station, Tohoku Shinkansen Line, East Japan Railway Company

Summary: On Friday, March 11, 2011, a ten--car train set departed from the Sendai rolling stock depot on time at 2:40 P.M. During the

train’s entrance into Sendai station at 72 km/h, the driver felt a strong tremor and noticed at the same time that the stop signal had been activated

in the cab signal. the driver immediately applied the emergency brake. After the stop, a review from inside and outside of the cars revealed that

both axles in the front bogie of the fourth car had become derailed to the left.

It was a test run, and 12 vehicle inspectors and one crew member were on board. However, no one was killed or injured.

At 2:46 P.M. on the day that “the Great East Japan Earthquake” occurred, which had a moment magnitude of 9 centered at the shore of Miyagi

Prefecture, the maximum seismic intensity of 7 was observed in the north of Miyagi Prefecture.

For details, please refer to the investigation report.(Published in Japanese on February 22, 2013)

http://www.mlit.go.jp/jtsb/railway/rep-acci/RA2013-1-1.pdf

The train stopped just after the cars received strong horizontal vibrations. After that, vehicle

inspectors confirmed the derailment. The train is presumed to have derailed due to the

seismic vibrations from the main shock of the Great East Japan Earthquake.

Findings

Considering the results of the vehicle movement simulations, the upper center rolling could

have been caused by the large shaking at the No.3 Odawara viaduct, which had a frequency

exceeding 1.5-1.7 Hz. Shaking of this magnitude is prone to generating upper center rolling

of an orthogonal direction in the rails).

It is somewhat likely that the external force of the Earthquake's seismic vibration caused the

train to undergo upper center rolling (*1), which means that the wheels of both sides severely

hit the rails as the train rolled.

*1 The rotating movement of

vehicles that is centered on the

antero-posterior axis is called

rolling; if the center of the rolling

is above the barycenter, it is called

“upper center rolling.” It is also

called “lower center rolling” if

occurs under the barycenter.

Whether the center of rolling is

upper, lower, or a combination of

both depends mainly on the

vibration frequency.

Probable causes: It is considered highly probable that the train was derailed by the seismic vibration of the main shock from the

Great East Japan Earthquake. It is also considered highly probable that, when the accident occurred there were no problems with

the railway facilities including the tracks, the train or any of its operations. Furthermore, the time of the derailment is thought to

be just after the time when the main shock from the Great East Japan Earthquake had arrived at Sendai city.

It is considered probable that out of the frequency components of the earthquake’s seismic

vibrations, the vibrations around 1.8 Hz, which are the natural frequency of the bridge, have

enlarged significantly by resonance, even more so than the other frequency ranges.

Movement of the train and cars just before derailment (conceptual diagram)

Vehicle Movement Simulation

We conducted a vehicle movement

simulation that was similar to the

method used to determine the cause of

the train derailment accident in the

Joetsu Shinkansen Line, which was

caused by the Niigata Chuetsu

Earthquake. (Simulation times are

shown on the left)

Coordinates

Left Right Left Right

Large lateral pressureon the flange of the right wheels

- Large lateralpressure on theflange of the leftwheels- The flange ofthe left wheelsmounted the rail

Track shifting to the left Track shifting to the right(b) Large lateral pressure on the left wheels just before 60.8

secWheel flange just above the rail at near 60.8 sec

(a) Large lateral pressure on the right wheels at near60.5 secLeft wheels rose 63 mm at near 60.6 sec

Situation of the train

Fourth car Third car

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The speed at the time of passing the edge of the tongue

rail was lower than the balancing speed for the cant.

Therefore, it is considered highly probable that,

compared to the static wheel loads, the load on the left

wheel increased while the load on the right wheel

decreased.

A train moved onto the turnout's tongue rail, traveled in the incorrect direction, and then derailed

Train derailment accident in Higashi-murayama Station, Seibuen Line, Seibu Railway Co., Ltd.

For details, Please refer to the investigation report.(Published in Japanese on February 22, 2013)


As described above, it is considered probable that the branch line side of the turnout was prone to producing climb-up derailments.

This is due to multiple factors. It is considered probable that this situation caused the vehicle to derail.

Probable causes: It is considered probable that this accident is thought to have the following background. The right wheel of the

first axle in the front bogie of the seventh car slid up onto the outer tongue rail of No. 67 curved turnout in the same direction.

This forced the train to enter the wrong direction to the main line side. The train was then pulled by its front cars in the branch

line, causing the seventh car to become derailed to the right of the branch line rail.

Findings

It is considered probable that at

curved turnouts in the same direction,

if there is an excessive difference in

the number of trains running between

the main line and the branch line, the

progress of abrasion in the rails will

be also different between the lines,

the gap between the main line rails

and the tongue line rails was occurred

to be a result of these differences, and

the reason that the tongue rail head

tilted towards the main rail.

At turnout No. 67, the curve radius rapidly reduced from 300 m to 184 m. It is considered probable that this leads the angle of

attack (*2) to increase.

With the increasing pressure to one of the axles from a

left wheel to the right direction (lateral pressure), in

addition to the decreased load on the right wheel, it is

considered probable that the derailment coefficient

probably increased. Derailment coefficient refers to the

ratio of lateral pressure and the wheel load.

It is considered probable that the tilt of the head decreased the

angle that the tongue rail made contact with the flange at. This

resulted in a lower threshold derailment coefficient (*1), which

made it easier for the train to run onto the tongue rail.

*1 The “threshold derailment coefficient” is calculated from the balancing

equation of the wheel loads and the lateral pressure that affect the point of

contact between the rail and wheel flanges when the wheel flange slides up on

the rail. The larger the coefficient of friction, or the smaller the angle of

contact (the angle of the wheel flange), the lower the threshold derailment

coefficient becomes. When a derailment coefficient gets larger than the

threshold, the possibility of derailment becomes greater.

*2 The “angle of attack” is the relative angle of the rolling wheel and the rail. The

larger the angle is, the more dangerous the derailment becomes.

Summary: On Saturday, December 24, 2011, an eight-car upbound train set departed from Seibuen Station on time. After passing

turnout No. 67 on the premises of Higashi Murayama Station at a speed of 32 km/h into Track 5 of the station, the driver of the

train felt as if the train was being pulled from behind when the front part of the train passed near I-RO turnout No. 66.

Immediately after noticing this, the driver checked the instrument and noticed that the driver-noticing light had turned off for a

moment. The driver then applied the emergency brake immediately. The train stopped after traveling for about 21 m after the

brake. A survey after the stop revealed that the first and the second axles in the front bogie of the seventh car had become derailed

to the right.

Out of the approximately 450 passengers and two crew members on board, no one was killed or injured.

(Presumed) process of the rightwheel’s climb-up derailment

(9) 400 mmThe right wheel ran onto theright tongue rail.There is a gap between theright main rail and the righttongue rail.

(5) 200 mmThe right wheel flange edgemade contact with the righttongue rail.The right tongue rail edgebecoming tilted.

(7) 300 mmThe right wheel ran ontoright tongue rail.The right tongue rail edgetilted toward the right mainrail.

Branch

side

Main

line

Right

tongue

rail

Right

main

rail

Direction

of travel

Distance fromthe tongue railedge

Tongue rail edge

Right tongue rail(1) 0 mmRight wheel flange cornermaking contact with the rightmain rail shoulder

Front bogie first axle

Right main rail

(3) 100 mmRight wheel flange edgemaking contact with theright tongue rail

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For details, please refer to the investigation report.(Published in Japanese on May 31, 2013)


Probable causes: This accident can be summarized as follows. It is considered probable that the hanger pins supporting the

reduction gear at the rear of the fourth fallen off and by the reduction gear dangled and damaged both the axles in the rear bogie of

the fourth car, as well as the first axle in the rear bogie of the fifth car to become derailed. The cars were burnt because of the

leaked light oil that scattered around the wooden rail sleepers from the fuel tank at the front of the sixth car, which was damaged

by the fallen bevel gear of the reduction gear. The oil caused the fire to break out near the generator or the rear edge surface of the

engine. The fire then spread across a wide area.

Findings

Operating with irregularly shaped wheels and dented

tread can give significant vibrations on unsprung

devices. It is considered probable that this leads to bolts

loosening and devices falling out.

It is considered probable that the reason the fluted hex

nuts’ hanger pins fell off could be due to the repetitive

effects of vibrations during the operation.

The hanger pins for the reduction gear fell off and then

the reduction gear and propeller shaft started hanging

down. This caused the reduction bevel gear on the

universal joint to begin making contact with the

propelling axle. After this, it is considered probable that

the bevel gear was further dangled, resulting in the

universal joint becoming locked and damaged.

The universal joint that was damaged could have led to the separation of the reducion gear

and the propeller shaft. The external cylinder and the joints of the shaft had then fallen off,

and lubricant oil had become scattered from the reducer. The reducion bevel gear dangled

down began making contact with the sleepers. On top of this, the damaged reduction gear

box then hit the dangled the reduction bevel gear, which is thought to have then caused the

rear bogie of the fifth car to be pushed up, resulting in the first axle becoming derailed to the

left.

The cause for the cars of the train to become burnt in this accident is thought to be the

damage to the fuel tank at the front of the sixth car. This caused the light oil to scatter around

the incinerated wooden rail sleepers. As a result, a fire broke out and spread from near the

generator or the rear edge surface of the engine. It then expanded into the cars by entering in

through their side windows.

Status of the burnt cars

Reduction gear parts fell from a diesel car that made contacted with a bogie, leading to derailment and fire

Train derailment accident at Seifuzan Signal Station, Sekisho Line, Hokkaido Railway Company

Summary: On Friday, May 27, 2011, a six-car upbound train set limited express train (Super Ozora 14) departed from Tomamu

station two minutes behind schedule. While running the train for Seifuzan Signal Station, the conductor, who was in the

conductor's cabin on the fourth car, heard unusual sounds and felt vibrations. The conductor notified the driver of the event. The

driver immediately made arrangements to stop the train in the signal station’s tunnel. Thereafter smoke from a fire that broke out

in one of the cars poured inside of the other cars. The driver tried to move the train out of the tunnel, but the train would no longer

start. The first axle in the rear bogie of the fifth car was derailed to the left, and the transmission at the rear of the fourth car was

damaged. The components of the broken transmission were scattered around the line from 2 km back from the place that the train

had stopped. The fire burnt all six of the train’s cars.

There were 248 passengers, the driver, the conductor and two crew members on board in the train. All of them escaped out of

the tunnel on foot. 78 passengers and the conductor got injured.

Direction

of travel

Reducion bevel gear (reduction gear yoke)

Cotter pin for retaining the reducer

Specialwasher

Transmission system in the vehicle

Rotating direction of thepropeller shaft

Power (from theengine)

Reduction prop bar

Propeller shaft

Propeller shaft (propeller yoke)

Split pin (in thefluted hex nut)Fluted hex nut

Rotating direction of thewheel

Universal joint

Reduction gear

Hanger pin

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For details,please refer to the investigation report.(Published in Japanese on July 26, 2013)


Pushing force was applied in the direction from the inside to

the outside rail while its wheelsets were running on the curve,

probably leading to an enlargement in lateral pressure on the

wheels on the outside rail.

With the significantly weakened fastening force of therail and the increased the irregularity of gauge, theleft wheels of the first axle in the first car fell betweenthe rails from the left rail head. It is consideredprobable that this caused the irregularity og gauge tobecome wider toward the right, causing all of the leftwheels of the second axle in the first car and behindto fall between the rails near the site.

The company did not have any knowledge or experience in

tightening the fastening bolts. As a result, the bearing capacity

of the rail fastening system near the accident site got lower

and lower as external forces from passing trains were

repeatedly applied on the system.

Over a period of two months prior to the accident, the

traffic of trains continuously reduced the capacity to

bear the rails. As a result, it is considered probable

that the irregularity of gauge have increased.

The irregularity of gauge exceeded the limit allowed in the

maintenance criteria from two months prior, when the rails

had been replaced. The degree of shifting is considered to

have become slightly larger after the replacement.

Summary: On Saturday, July 28, 2012, the driver of a two-car upbound train set noticed unusual sounds and shocks

when stopping at Kamihori Station during a one-man operation. The driver applied the emergency brake to

immediately stop the train. A check after the stop revealed that all the eight axles of the car had become derailed.

There were twenty passengers and two drivers on board the train. No one was killed or injured.

Damage of inserts of rail fasteners on PC

Probable causes: It is considered probable that, at the outlet-side transition curve of the left-hand curve that is

followed by a reverse right-hand curve, the lateral displacement of track (the shifting of track) was larger than

allowed by the maintenance criteria. This decreased fastening force of the rail fastening system and made the action

of lateral force associated with the running of the train extend the gauge, leading to the derailment of the left wheels

between the rails.

Direction of travel →

Relationship between therails and wheelset

Wheel widthBack gauge

Thickness of flange

Inside railFall

Outside rail

Gauge

Wheel width + back gauge + thickness of flange

Sketch of the accident site

For Minami-toyama

(Platform)

The train

Trace of derailment beginsNearly 2k214 m

Edge of platform2k190 m

Right curve (R250)

Left curve (R300)

(Straight)

Horikawa Yosui Bridge2k242 m

Direction of travel For Iwakuraji

(Straight)

2k237 m

2k2122k186 m

Stop position(Front: nearly 2k176 m)

By the fastening force of the rail fastening system degraded,facilitated gauge expansion due to lateral

pressure, leading to derailment

Train derailment accident between Kosugi Station and Kamihori Station, Kamitaki Line Toyama Chiho

Railroad Co., Ltd.

Findings

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Alandslide caused by heavy rain piled up earth and sand on the track, causingderailment

TrainderailmentaccidentbetweenOppamaStationandTauraStation,MainLineofKeikyuCorporation

For details, please refer to the investigation report.(Published in Japanese on September 27, 2013)


Probable causes: It is considered highly probable that this train derailment accident was caused by the accumulated

earth and sand, which contained a concrete foundation, flowing down from the collapsed slope face, and then the

front bogie ran onto them. It is considered highly probable that the concrete foundation that came into contact with

the first car's bogie made the situation even worse. It is considered probable that the cause of this landslide is to be

the rise in the level of groundwater in the surface of the slope. It is considered somewhat likely that this happened

due to the large amount of rainwater that fell on the surface, as well as on the top of the bedrock layer under the

surface, which had possibly become fragile. It is unclear why the steel fences’ concrete foundations, which were built

on the slope, fell down. This is due to a lack of records detailing the reasons for building the fence, or structural

drawings. However, it is considered somewhat likely that the cause was the deterioration of the foundation, in

addition to the flow of an amount of earth and sand that was larger than expected in the original plan.

調査の結果

Summary: On Monday, September 24, 2012, an eight-car train set departed from Oppama station one minutebehind schedule. During a coasting operation at 72 km/h, the driver noticed a pile of earth and sand on therailway approximately 30 to 40 meters ahead. Although the driver immediately applied the emergency brake, itwas too late to avoid running onto the piled-up sand. The train stopped after traveling approximately 84 mfurther. All four axles in the first car, both the axles in the front bogie of the second car, and both the axles inthe front bogies of the third car became derailed to the right. When the train stopped, the section of the trainfrom the first car to the middle of fourth car was in the tunnel.

Out of the approximately 700 passengers and two crew members on board the train, 55 passengers and thedriver were injured.

Although the area (including the landslidesite) above the cut slope face where the steelfences were is private land, it is consideredhighly probable that the area (including thefences) had been viewed as a survey area thatshould be paid attention to.

It is considered probable that the surface, aswell as the top of the bedrock layer under thesurface around the site of the landslide, hadbecome fragile due to the long-term influenceof rainfall and springwater.

Earth and sand containing large amounts ofwater from heavy rain flew down from theslope failure nearly 20 m above the steelfences. It is considered probable that themultiple concrete foundations collapsed inthe slope or fallen to the bottom of the slope.

It is considered highly probable that a largeamount of rain was falling for a short timearound the slope at the time of the accident.

It is considered highly probable that the traincollided with a pile of earth, sand, and one ofthe concrete foundations, which had allbecome accumulated on the track. The frontbogie then ran onto the foundation, resultingin derailment, with the bogie jumping up onemeter. Conditions of the slope and landslide site

Findings

Foundation (pelite)

Topsoil, talus sediment

View from the track (Dec. 2009, Keikyu’s photo)

View from the track (Apr. 2011, Keikyu’s photo)

Landslide site after removing the earth and sand (Nov. 2012)

Landslip point(W: Approx. 10 m, L: Approx.

11.5 m, D: Approx. 3 m max.)

Steel Fences (Damaged)(W: Approx. 10 m, H: Approx. 4m, Concrete Foundations:estimated to 7)

Nearly 11.5 mSteel fences before destruction

Keikyu’s railway site

Top of cutting slope

Rockfall barrier(Partly damaged)gunite-shooting

(estimated to be approx. 50 mmthick)(Partly destroyed)

Nearly 16 m

Nearly 12 m

Nearly

17 m

Nearly 40 m

Nearly 32 m

Land

boundary

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chapter 3 railway accident and serious incident investigations · chapter 3 railway accident and...

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